In modern medicine, the biopsy, i.e., removal of material from a living human or animal body for examination by various methods such as microscopy, is carried out routinely. Typically, a method of this type is used for the diagnosis of premalignant and malignant cell transformations, which indicate the presence of cancerous or precancerous tumors. The routine techniques known as core biopsies, in the course of which complete tissue segments are taken for histological examination, make use of various types of hollow needle-like biopsy instruments. These instruments have needles with a sharp frontal edge or a notched stylet in order to cut into the tissue upon insertion into the selected area of the body. The tissue piece to be removed as a biopsy sample is taken up into the cylindrical bore of the cannula. When withdrawing the biopsy instrument from the body, the sample is retained in the cylindrical bore by mechanical means or by suction and is separated from the main body of the tissue during the withdrawal procedure. The samples typically have a generally elongated cylindrical shape or a longitudinal semi-cylindrical shape. The quality, e.g. the width, length and the proportion of crushed cells of biopsy samples for histological or cytological examination is an important factor that influences the study results. Tissue biopsy samples should reflect the structure of the living tissue as closely as possible. Accordingly, tension on the samples during excision and removal of tissue, as well as during removal from the cannula, should be avoided.
The removal of material from a living human or animal body for subsequent diagnostic procedures is usually done by obtaining a solid tissue sample by biopsy or by the removal of body fluids, e.g. in the form of a vascular puncture for obtaining a blood sample or by thoracentesis to obtain a pleural effusion, or joint aspiration for the production of synovial fluid, or by spinal canal puncture to obtain liquor, or generally by the puncture of a body cavity system for the extraction of material in liquid or liquid-like form. The present invention describes a biopsy instrument that allows, in a surprisingly simple manner, cellular or molecular samples in different cavity body systems of humans and animals to be enriched prior to removal, to ensure a sufficient concentration for downstream diagnostic procedures. Based on this biopsy instrument, corresponding technical instructions and guidelines that describe new or improved diagnostic procedures can be formulated.
U.S. Pat. No. 5,282,476 describes an automated device for the biopsy, in which the needle is attached to a stylet that guides the needle to the biopsy site. After insertion, the needle is driven out over the stylet, removing the sample with it. A means of suction is used to hold the sample in place. However, because of the means of suction, this biopsy instrument has a rather complex structure and requires considerable skill in handling. In the hands of an inexperienced user, the instrument can give uncertain results. It is also designed for the removal of material from solid body structures and not from body cavity systems.
In addition, instruments or sensors are known that serve to enrich the samples. WO/2006/131400 describes the use of a functionalism surface for the enrichment and recovery of molecules or isolated cells, such as from fetal trophoblasts in the maternal blood circulation. These are receptor structures anchored on the surface of the sensor, responding to specific cells or molecules in the bloodstream and, thus, permitting enrichment of this material in situ prior to physical removal from the body. However, to-date no embodiment of a biopsy instrument suitable for this task has been described that would allow manufacturing for use in humans and animals.
Furthermore, in the prior art, devices are described (for example, WO 01/23031 A1, EP 1779816 A2, US 2003/0135153, WO 98/22022 A1), with the aid of which certain drugs or dyes can be inserted into body cavities. Here, the active ingredients are introduced into the hollow sections of the devices and released upon reaching the target position. The disadvantage here is that the samples are obtained in a very inexact manner and the active ingredients are introduced into the devices in liquid form. In this way, the possible uses of the devices are limited.
The means described in the prior art for the removal or enrichment of samples cannot be used in all areas of the body. In particular, the endoscopic use of the described instruments/sensors is not possible or can only be performed with difficulty. Other major drawbacks are the precision with which the tissue area selected for the biopsy, and body cavity systems in particular, can be targeted with the instrument/sensor, the ease with which the instrument/sensor can be handled, injury caused to the patient by the procedure, as well as the cost of the instrument or sensor. In addition, no biopsy instrument is described that is designed for use in humans and animals to allow enrichment of the biopsy material in a low-risk way prior to removal of the samples from body cavity systems.